Another lighting thread, 75' F350 Crew

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Dec 11, 2011 | 07:46 PM

78bigunns

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Posting Guru

Joined: Oct 2001

Posts: 1,777

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From: Culpeper, Virginia

Another lighting thread, 75' F350 Crew

Took out the truck for it's 1st major road run.

Drove excellent, shifted smooth, overall very good run.

Stopped at a friends to help on a trans install.

Driving home in the dark (1st time), I need to address some issues.

Dash lights are dim, with dimmer **** set to full brightness. Doesn't help that the right side of the dash is out.

Headlights are both new, and I cleaned grounds I found from each to the radiator support.

All exterior lights work, but the headlights leave alot to be desired. All signals, hazards, brake, running lights work.

Inside, all lights are dim.

I'm thinking I need address the grounds. Is the strap from the firewall to the intake the main source of dash grounding?

Would having that strap bolted to the aluminum intake cause a poor ground?

I was thinking of pulling the cluster and cleaning the bulb buckets. Also planning on pulling the alternator and having it tested.

Any ground I have found, I have cleaned to bare metal and checked the connection itself.

Is there a schematic for all ground locations somewhere?

My searching is showing up mostly LED stuff, headlight conversions, things like that.

Thanks.
Blair

Dec 11, 2011 | 08:03 PM

HIO Silver

Fleet Owner

Joined: Dec 2009

Posts: 20,678

Likes: 82

From: NorCal

Fords' headlight wiring circuit leaves alot to be desired. Basically, the voltage goes through the switch then to the headlights. A better set-up is to use LMC's headlight relay kit which connects the headlights directly to the battery and the headlight switch power is used as the signal to engage the relay. Around $30 and highly recommended from those who use it.

The voltage regulator is a POS. Replace it with a solid state version and you'll likely see improvement. However, I'd ditch it and go with a 130-amp 3G alternator upgrade. Search this forum for multiple threads.

With the dash, it could be as simple as dirty bulbs. Some in here have retrofitted LEDs from LED Lights, Bulbs & Accessories - SUPER BRIGHT LEDS

Cleaning up bulbs, sockets. and terminals is a good thing . I also suggest applying dielectric grease.

Here are some wiring diagrams:
<A HREF=http://i55.tinypic.com/21jw50l.jpg>74-78 Wiring Diagram Pt1</A>
<A HREF=http://i52.tinypic.com/35luc8n.jpg>74-78 Wiring Diagram Pt2</A>

More detailed diagrams can be found at http://www.Fordication.net

Grounds - Engine to cab, cab to frame, and bed to frame. Redundant grounds are a good thing too.